German Patent DE 72 25 662 U1 discloses an apparatus which has a filter membrane and a main body located upstream from the filter membrane, which body has a supply channel running perpendicular to the surface of the filter membrane and a gap running between it and the filter membrane for the formation of a tangentially directed transverse flow and a return channel. There, a tangential or transverse flow filtration is essentially carried out.
The problem thereby arises of removing undesired components from a liquid with an accumulation of such undesired components, such as particles, microorganisms, chemical substances, such as oils and the like. In this respect, the use of separators, using centrifugal force, or a simple sedimentation, are generally known. Centrifuges have an expensive structure, make high demands on the material and the manufacturing precision because of the required high centrifugal accelerations and are therefore expensive, susceptible to disturbances, and maintenance-intensive.
For a high degree of separation, the sedimentation requires large volumes, on the one hand, and a relatively large time period, on the other hand.
U.S. Pat. No. 5,183,569 A1 also shows a filter apparatus with a filter membrane, in which the loaded fluid is circulated in a closed cycle.
In order to attain a high throughput, for example, centrifuges in parallel operation or so-called separators are used. The separators consist of large thick containers, in which numerous thin plates are above one another, parallel, at a distance to each other and at an angle with respect to the symmetrical axis of the container. These plates are rotated at a high rpm (up to 6000 rpm). The interior is filled via an inlet and with the rapid rotation of the plates and the resulting segregation, fluid components of different densities are separated so that the heavier components along the inclined plates are deflected downwards and the light components, upwards, where they are respectively conducted away.
The problem of the invention under consideration is to improve the filter apparatus of the type mentioned in the beginning to the effect that a very extensive, continuous removal of the fluid components to be separated or to be disposed of is possible, wherein the filter apparatus, to a large extent, works free of maintenance and is of simple construction. Furthermore, if at all possible, no movable components should be required.